1. Field of the Invention
The present invention relates in general to a lumbar support for a seat and more particularly to a lumbar support of the kind consisting of a support shaft rotatably installed at its opposite ends on a seat back frame and a support panel installed on a cranked portion of the support shaft for forward and rearward movement therewith.
2. Description of the Prior Art
It has heretofore been desirable for an automobile or the like to have a seat which is capable of stably supporting a seated occupant while providing seating comfort and minimizing fatigue of the seated occupant.
To this end, a seat is provided with various additional support mechanisms. One of such known support mechanisms is a lumbar support provided to a seat back frame to support thereon the lumbar section of a seated occupant.
An example of a prior art lumbar support is disclosed in Japanese Utility Model Provisional Publication No. 63-17654.
A problem of the prior art lumbar support is the need for a stopper member that is welded or otherwise secured to a support shaft for limiting movement of a support panel relative to the shaft, thus increasing the number of constituent parts and the manufacturing and assembling expense.
Another problem is that the support shaft needs to have at opposite ends thereof stepped shaft portions which requires costly machining to produce. A pair of bushing nuts is needed for attachment to the stepped shaft portions for limiting movement of the shaft in the axial direction thereof, thus further increasing the number of constituent parts and the manufacturing and assembling expense.